Cranks but will not start on 1990 GMC 1500 Pickup

Moved vehicle out of carport,ran fine.After about 2 hrs would not start.Timing is right on,even changed timing chain and cam gear.Plugs are not wet,constantgood fire to plugs.Cranks fine and feels like it will almost start.This has a throttle body,Canadian model with usa emmision standards.

Asked by for the 1990 GMC 1500 Pickup
I'm suspicious of a failing fuel pump. Safely check your fuel pressure
It should start for a bit if spraying quick start,but it does not.I relpaced the sending unit last summer and the fuel pump tested fine.Now i'am thinking a possible short in the throttle body injectors or wiring or that the starter itself not turning the engine fast enough.
Thank You.